The present invention relates to hydraulic release mechanisms for vehicle clutches, and more particularly to an improvement of an hydraulic clutch release mechanism of the type which includes a push-rod axially slidable within an input shaft of a power transmission unit and being engaged at its one end with a release member of a vehicle clutch and an hydraulic cylinder attached to a housing assembly of the transmission unit to urge the push-rod toward the release member causing disengagement of the vehicle clutch.
In conventional clutch release mechanisms of this kind, the property of fluid supplied to the hydraulic cylinder is usually different from that of lubricating oil stored within the transmission housing. If an amount of the hydraulic fluid flows into the transmission housing from the cylinder, it will damage seal members of synthetic rubber which are adapted to the transmission unit.